While they’ve made strides in arresting illegals and building a fence along the U.S.-Mexico line, the Border Patrol only has “operational control” of 44 percent of the southern border, and of that only 15 percent is air tight, according to new General Accountability Office report.

The GAO said that the Mexican border with Texas has the most holes, especially between Fort Hancock and Brownsville, where 70 percent to 90 percent of the state line is at the two lowest levels of protection, “monitored” and “low-level monitored.” The GAO said that efforts to detector stop illegal immigrants from crossing there were poor. “Border Patrol reported that these two levels of control were not acceptable for border security,” said the GAO.

Highlights from the new report:

– Of the nearly 2,000 miles separating the U.S. and Mexico, 873 are under the “operational control” of the Border Patrol.

– Of those 873, 129 miles were under full control, with the rest classified as “managed.”

– Kudos to the Yuma, Arizona unit whose section of the border is locked down.

– Protecting the southern border costs taxpayers $3 billion a year. Last year, the agents caught 445,000 illegals and seized over 2.4 million pounds of marijuana.

– Each year the southern border gets harder to cross due to the hiring of Border Patrol agents, who’ve gone from 10,000 in 2005 to 17,000 today, and the installation of fencing that now stretches over 649 miles.